1996 dodge interpid blows heat on low speeds but when you turn the blower on high it blows cooler?

you cant flush those radiators out and get them really clean sometimes so replacing it may be the only option you have, they are cross flo radiators and they don't flush out real good and most of the time if the bottom of it stops up that's the end of the coolant circulating real good in it,and that may be the loss of heat on it,yo need to also make sure the block has been thoroughly flushed out on it some of the junk from flushing it out will wind up back in the heater core also,good luck.

Flush it, flush it, flush it. Half of your radiator is cold because of poor circulation. That's the trouble with the hearer,too. There is so little heat in the water there and it circulates so slowly, the blower makes it cold when on high speed.